Container With Flexible Walls

ABSTRACT

The subject matter of the invention is a container with flexible wails. The container includes an opening provided with means for keeping it open, said means having two flexible elongate elements connected at their ends by a first articulation and a second articulation. The first and second articulations are configured to bring the two flexible elongate elements one against the other in a first configuration and to separate the two flexible elongate elements in a second configuration. In the second configuration, the two flexible elongate elements are turned over on themselves with respect to the first configuration. The two flexible elongate elements are at least partially formed from a flexible band, and the first articulation includes a cut in a pail of the thickness of the band, said cut being oriented towards the outside of the container in the first configuration.

The present invention concerns a container with flexible walls comprising an opening provided with means for keeping it open.

It finds particular application in the field of the manufacture and use of bags in particular made from plastics material, for example for packaging rubble in the building and civil engineering sector, this example not being limitative.

Bags are commonly used produced from flexible sheets of polymer plastics material or any other material including of vegetable origin and comprising an opening through which the objects to be packaged are introduced. This is particularly the case in the field of building and civil engineering for recovering and disposing of rubble.

Normally, such bags have a simplistic structure without any particular arrangement for facilitating the introduction of the rubble and in particular for keeping the opening of the bag in the open position.

The document FR-A1-2 855 501 proposes a solution to this difficulty and provides a container comprising an opening provided with means for keeping it open, these means including two flexible bands bordering the opening of the container and connected at each of their ends by a pivot articulation. The holding in the open position is effected by a limitation of the amplitude of the pivot articulation, in particular to 180°, so as to keep the flexible bands separated when they are pivoted by turning by the wails of the container.

This prior device gives satisfaction overall However, the manufacture thereof is relatively complex because of the type of product concerned, generally at low cost price.

The document FR-A1-2 894 512 proposed a method and installation for manufacturing a container provided with means for keeping its opening open, it employs two flexible bands that are joined during manufacture. Fairly difficult manufacturing steps ensue.

The present invention remedies ail or some of the drawbacks of the techniques known up until the present time and for this purpose proposes a container with improved flexible walls.

The invention proposes to attach, at the top end of the container, namely at the opening thereof, a device provided with means for keeping the opening open. These means comprise two flexible elongate elements that are connected at their ends by first and second articulations. These articulations are configured so as to bring the two elements against each other in a first configuration and to separate the two elements from each other in a second configuration in which the two elements are turned over on themselves with respect to the first configuration.

According to one possibility of the invention, the two elements are at least partially formed in a flexible band, the first articulation comprising a cut in part of the thickness of the band, Advantageously, said cut is oriented towards the outside of the container in the first configuration. According to an advantageous possibility, the second articulation is formed in an identical fashion to the first, namely by a cut in part of the thickness of the band.

It will easily be understood that it is possible, by virtue of the invention, to produce the device keeping the opening of the container open in an optimised fashion in particular by means of two cuts each implementing one of the articulations.

According to a preferred embodiment, furthermore, this design operates using a single flexible band, the cuts being effected by one face of the flexible band, the ends of the flexible band then being joined by simple welding or adhesive bonding.

The band is a single piece of material Thus only one piece is used during the manufacture and the implementation phases are reduced to two cuts and one assembly. Whereas it would have been considered that the formation of the articulations by cutting would not afford sufficient strength for the container, in particular in the open position, the present invention combats this prejudice. In particular, the cuts, solely partial through the thickness of the flexible band, despite everything allows sufficient strength for using the container in a suitable fashion.

In addition, whereas FR-A1-2 855 501 tends to make it thought that the connection between the bands is to be effected at each end of the latter, the present invention produces the articulations at the junction between the flexible elements, at each of the ends thereof. If was found surprisingly that this embodiment, when the device is put in its second configuration, made it possible, by simple pressing of the portions of the articulation through the thickness of the flexible band, to effect the holding in the open position. The pressing produced in this position, thickness against thickness in the flexible band, was not foreseeable.

Finally, whereas the prior art encourages forming the means for keeping the opening open with two clearly differentiated and distinct elements, the invention combats this prejudice by basing the assembly in a single piece, namely the flexible band.

Other aims and advantages will emerge during the following description, which presents a detailed embodiment of the invention which however does not have the purpose of limiting it.

First, various advantageous but non-limitative embodiments of the invention are introduced below, which can be implemented alternately or cumulatively:

-   -   the height of the cut is between 30% and 90% and more         advantageously still between 50% and 80% or between 50% and 70%         of the thickness of the band,     -   the height of the cut is equivalent to ⅔ of the thickness of the         band,     -   the direction of the cut is perpendicular to the face of the         band opposite to the cut,     -   the two elements are formed entirely from the band, the ends of         the band being connected together,     -   the band is made from high-density polypropylene,     -   the band is made from extruded high-density polypropylene,     -   the band is made from polyethylene,     -   the band is made from biopolymer or other vegetable matter,     -   the first articulation comprises, on the face opposite to the         cut, a reinforcement layer opposite to the cut,     -   the second articulation is similar to the first articulation,     -   one of the elements comprises an adhesive member on its face         that is situated outside the container in the first         configuration,     -   at least one of the cuts comprises, at its edges, a bulge         producing a local protrusion of the band,     -   the bulge has a thickness increasing in the direction of each         edge of the cut,     -   the maximum thickness of the bulge is 10% greater than the         thickness of the band.

The invention also concerns a method of manufacturing a container comprising the following steps: formation of two cuts from the same face and part of the thickness of a flexible band, the cuts being spaced apart by a length equal to half the length of the band, and connecting of the two ends of the band.

Advantageously, the method comprises the formation of a bulge around at least one of the cuts so as to produce a local protrusion of the band.

The accompanying drawings are given by way of examples and are not limitative of the invention. They represent only one embodiment of the invention and will make it possible to understand it easily.

FIG. 1 shows an example embodiment of a device constituting the means for keeping the opening open according to a preferred embodiment.

FIG. 2 is a plan view whereas FIG. 3 shows a detail of FIG. 2 illustrating in particular a movement of the articulation,

FIG. 4 presents a possibility of bringing the elongate elements closer together and further away from each other and FIG. 5 gives a detail thereof at an articulation.

FIGS. 6 and 7 are views similar respectively to FIGS. 4 and 5 in a more open position of the container.

FIG. 8 presents in perspective the device presented in the figures previously introduced.

FIG. 9 illustrates a possibility of turning the device over on itself in order to pass from a first configuration presented in FIGS. 1 to 7 to a second configuration appearing in FIGS. 10 and 11.

FIG. 10 is a plan view of the device including the means for keeping the opening open in the second configuration, with articulation cuts oriented towards the inside of the container. FIG. 1 shows a detailed view thereof. FIG. 12 shows a container equipped with the device previously illustrated substantially at its top part. Whereas FIG. 12 is a front view of the container, FIG. 13 is a profile view thereof. FIG. 14 shows in perspective a use of the container of the invention with means for keeping the opening open in the active position, according to the second configuration.

FIG. 15 shows a possibility of formation of a cut.

The form and material of the container 1 are not limited. It may be a case for example of a container 1 in the form of a bag made from polymer plastics material comprising two side walls 2, 3 produced by sheets of polymer plastics material substantially rectangular in shape and joined by three of their edges. It is also possible to form a supplementary bottom portion, gussets or any other additional arrangement without departing from the scope of the invention.

The non-joined edges of the side walls 2, 3 define an opening 4 for introducing objects to be loaded into the container 1.

The invention comprises means for keeping the opening 4 open during the loading phase.

In the case of FIGS. 12 to 14, these means have been shown situated at the top end of the container 1, directly at the edge of its opening 4. However, these means could be situated at other levels, in particular at a level at a lower height, in the direction of the bottom of the bag.

A description is more precisely given below of a preferred embodiment of the means for keeping the opening 4 open.

More particularly, in FIG. 1, an elongate element 5 here substantially in the form of a flattened rectangular parallelepiped is referenced 5.

FIG. 2 shows, seen from above, the device so that a complementary elongate element 6 is depicted. Advantageously, the elongate elements 5 and 6 have identical forms and dimensions. They are joined at each of their ends by a first articulation 7 and a second articulation 8.

Although this is not necessary, it is advantageous to produce the articulations 7 and 8 identically in order to optimise the manufacturing process. At the least, a first articulation 7 from the articulations 7, 8 comprises a cut formed in a band constituting at least partially one or other or both of the elongate elements 5, 6. A particularly advantageous solution consists of using a flexible band for producing all the elongate elements 5, 6.

Preferably, the band, and advantageously all the elongate elements 5, 6, are produced from a polymer material and configured so as to preserve a flexibility providing sufficient flexion to achieve the opening of the container 1 in the configurations appearing in FIGS. 6 and 10 without causing rupture of the elongate elements 5, 6.

By way of example, use is made of a band made from polymer material of the polypropylene type and more particularly high-density polypropylene obtained by extrusion. The use of this material is particularly advantageous since it was found that this material had mechanical properties equivalent to those of a fibrous product, with increased mechanical strength along the length of the flexible band, in this way, despite the cut made at the first articulation 7 and optionally at the second articulation 8, the mechanical strength is sufficient to maintain coherence between the elongate elements 5, 6.

The substantially laminar mechanical behaviour of extruded high-density polypropylene ensures the formation of a residual layer on this side of the cut, providing articulation under good conditions of mechanical strength and flexibility.

Alternatively, it is possible to use polyethylene or other polymers including those of vegetable origin (biopolymers). It is also possible to use a non-transformed vegetable matter. For example, bamboo can be used. More precisely, a bamboo rod is cut along its length so as to keep only a slightly curved strip. The strong fibrous character with fibres oriented longitudinally provides the mechanical strength of this strip even after the articulation cuts. Other woods, advantageously highly fibrous, can be used. Moreover, another advantageous possibility is reinforcing one or other or both of the articulations 7, 8 by a reinforcement layer connected to the rear face of the articulation, the face opposite to that of the cut. By way of example, a reinforcement layer of the adhesive type with textile layer can be used.

FIG. 6 shows more precisely the production of the cuts 10, 11. These are advantageously produced at an orientation perpendicular to the plane of the faces of the flexible band serving as a basis for producing the elongate elements 5, 6 and over the entire width of the band. Advantageously, the cuts 10, 11 are produced so as to avoid or minimise the removal of material. Thus it is ensured that, in the open position, the adjoining ends of the elongate elements 5, 6 are in abutment across the thickness of the elements 5, 6, producing substantially an alignment as appearing in FIG. 7. It is desirable not to produce a notch at the articulations 7 and 8. The cut 10, 11 can be limited to a simple separation of the band into two portions. In particular, a thin blade can be used for producing the cut.

Still preferably, the thickness of cut is between 50% and 70% of the total thickness of the band. Advantageously, the cut is around ⅔ of the thickness of the band so that the flexible part producing the articulation forms approximately the residual third of the thickness.

By way of non-limitative examples serving to illustrate possible embodiments, it is possible to use the following dimensional parameters:

-   -   thickness of the flexible band, and consequently of the elongate         elements 5, 6: between 0.2 and 0.8 millimetres. One solution         that has given satisfaction: using a band 0.4 millimetres thick;         according to another possibility, the thickness of a band, of         polypropylene in particular, is 1 millimetre. The notch of the         cut can then for example represent 80% of the thickness, that is         to say here 0.8 millimetres;     -   width of the band lying between 5 and 20 millimetres and for         example 14 millimetres. Moreover, a width of band of around 10         to 40 times greater than its thickness may give satisfaction;     -   length of the elongate elements 5, 6: between 300 and 500         millimetres.

When the means for keeping the opening open are produced from a single band, the manufacturing method used may, the band being flat and accessible through one of its faces, provide a cut at least at the articulation 7, and advantageously a similar cut at the articulation 8. At least one of the cuts 10, 11 is produced by means of a blade 14 with a profile splayed towards its base. The angle of the splayed profile of the blade 14 may be between 5° and 10°. This involves a variation in thickness of the blade and, therefore, a variation in the width of the notch, decreasing towards the bottom of the cut 10, 11. During its descent into the band, the blade produces a plastic deformation of the material of the band, in particular, the band advantageously comprises a bulge 15 of material on the face of the band through which the cut is made, around said cut. This bulge 15, with a profile preferentially increasing towards each edge of the cut, forms a slight increase in the thickness of the band close to the cut 10, 11, This protrusion may represent a maximum of between 10% and 20% of the thickness of the band, that is to say 0.2 millimetres for a band 1 millimetre thick.

The presence of a bulge 15 around the cut locally increases the contact surface between the two edges of the cut, thus increasing the effect of keeping the container in the open position. Advantageously, this bulge does not involve an additional manufacturing step since it is produced at the time of the cut. In addition, the thickness of the rest of the band is not modified, which preserves its flexibility and avoids over-consumption of material.

It is arranged for the cuts 10, 11 thus formed to be spaced apart by a length equivalent to the length of the elongate elements 5, 6. Next it suffices to fold the band on itself so as to apply the element 5 against the element 6 as appears in FIGS. 1 and 2. At this stage, the free ends of the band are assembled by any normal means, which may include the addition of a fixing device or the formation of an assembly of the welding or adhesive bonding type. In the latter case, it is advantageous for the flexible band to have a length slightly greater than the sum of the lengths of the elongate elements 5, 6. In this way, an overlap portion is preserved, allowing the formation of a fixing area 9 for welding.

It should be noted that at least one of the elongate elements 5, 6 may comprise an adhesive member on its face situated outside the container 1 when the latter is in the first configuration. By way of example, an adhesive member 12 can be produced in the form of double-face adhesive, from which it is possible to remove a protective film when it is wished to close the bag. The closure is then effected by folding the elongate elements 5, 6 over one of the wails 2, 3 of the container 1 so that the adhesive 12 produces its effect on said wall.

The first configuration of the means for keeping the opening open appears in FIGS. 1 to 7 and in FIGS. 12 and 13. In this situation, the elongate elements 5, 6 have a propensity to move together so that the opening of the bag is not preserved. The user may on the other hand, by exerting a separation movement on each of the elongate elements 5, 6, effect the opening of the container as is clear in FIGS. 4 to 7. In this configuration, the cuts 10, 11 of the articulations 7, 8 are oriented towards the outside of the container 1. The flexibility of the elongate elements provides an elastic return to the closed position.

FIGS. 8 to 9 show a possibility of passing from the first configuration to a second configuration. In FIG. 8, the elongate elements 5, 6 are distant from each other. It is not necessary for this separation to be maximum. The operator can then effect an advantageously symmetrical movement on the two elongate elements 5, 6 so as to turn them over on themselves. Naturally, the result of this operation is that the face of the elongate elements 5, 6 up until then situated towards the outside of the container 1 in the first configuration is oriented towards the inside of the container 1. The second configuration is then reached. It corresponds to the views in FIGS. 10, 11 and 14. It will be noted that the cuts 10, 11 are then oriented towards the inside of the container 1.

FIG. 11 shows more particularly the relative situation of two ends of the elongate elements 5, 6 at the articulation 7 and the function of the cut formed at this level in order to effect an abutment across the thickness of the elements 5, 6 able to hold the device in an open position keeping the opening 4 of the container 1 open.

The overall result is particularly well illustrated in FIG. 4. It can be seen that the operator can use it, without having to effect a residual force on the bag, its opening 4 remaining open.

The cuts 10, 11 are advantageously produced across the width of the elongate elements 5, 6, in an orientation perpendicular to the length of these elongate elements 5, 6.

REFERENCES

-   1. Container -   2. Side wall -   3. Side wall -   4. Opening -   5. Elements -   6. Elements -   7. First articulation -   8. Second articulation -   9. Fixing area -   10. Cut -   11. Cut -   12. Adhesive member -   13. Opposite face -   14. Blade -   15. Bulge 

1. A container with flexible walls comprising an opening provided with means for keeping it wide open, said means having two flexible elongate elements connected at their ends by a first articulation and a second articulation both configured to bring the two elements one against the other in a first configuration and to separate the two elements in a second configuration in which the two elements are turned over on themselves with respect to the first configuration, wherein the two elements are entirely formed from a flexible band, the ends of the band being connected, and wherein the first articulation comprises a first cut in a part of a thickness dimension of the band, said first cut being oriented towards outside of the container in the first configuration, and wherein the second articulation comprises a second cut in a part of the thickness dimension of the band, said second cut being oriented towards the outside of the container in the first configuration.
 2. A container according to claim 1, wherein a height dimension the first cut is between 50% and 80% of the thickness dimension of the band.
 3. A container according to claim 2, wherein the height dimension of the first cut is equivalent to ⅔ of the thickness dimension of the band.
 4. A container according to claim 1, wherein the first cut has a direction that is perpendicular to the face of the band opposite to the first cut.
 5. A container according to claim 1, wherein the first and second cuts are spaced apart by a length equal to half a length dimension of the band.
 6. A container according to claim 1, wherein the band is made from high-density polypropylene.
 7. A container according to claim 6, wherein the band is made from extruded high-density polypropylene.
 8. A container according to claim 1, wherein the band is made from polyethylene or biopolymer or other vegetable matter.
 9. A container according to claim 1, wherein the first articulation comprises, on a face opposite to the first cut, a reinforcement layer opposite to the first cut.
 10. A container according to claim 1, wherein the second articulation is similar to the first articulation.
 11. A container according to claim 1, wherein one of the two elements comprises an adhesive member on its face that is situated outside of the container in the first configuration.
 12. A container according to claim 1, wherein at least one of the first and second cuts comprises, at its edges, a bulge producing a local protrusion of the band.
 13. A container according to claim 1, wherein the bulge has a thickness increasing in the direction of each edge of the said one of the first and second cut.
 14. A container according to claim 14, wherein the bulge comprises a maximum thickness that is 10% greater than the thickness dimension of the band.
 15. A method of manufacturing a container with flexible walls comprising an opening provided with means for keeping it wide open, said means having two flexible elongate elements connected at their ends by a first articulation and a second articulation both configured to bring the two elements one against the other in a first configuration and to separate the two elements in a second configuration in which the two elements are turned over on themselves with respect to the first configuration comprising the following steps: forming the first and second cuts from a same face and part of the thickness dimension of the flexible band, the first and second cuts being spaced apart by a length equal to half a length of the band; connecting together of the two ends of the band.
 16. A method according to claim 15, comprising the step of forming of a bulge around at least one of the first and second cuts so as to produce a local protrusion of the band. 